Background:Repetitive tensile stresses from valgus torque can induce elbow injury in adolescent baseball players. Insufficient hip range of motion (ROM) can change throwing mechanics, reducing the transfer of energy from the lower to the upper extremities. Thus, hip ROM limitations may force the upper extremities to bear the burden of a strong throw. Improper pitching mechanics caused by insufficient hip ROM are thought to increase valgus torque on the elbow when throwing, increasing the risk of elbow injury.Purpose:To investigate the relationship between elbow pain and hip ROM in adolescent baseball players.Study Design:Cross-sectional study; Level of evidence, 3.Methods:A total of 122 adolescent baseball players with a mean age of 12.0 years (range, 6-14 years) participated in this study. Elbow pain, hip flexion angle, and the internal rotation angles of the hip at 0° and 90° of flexion were assessed. Participants were divided into a pain group and a normal group based on the pain assessment, and each hip angle was compared between groups using Student t tests. P values <.05 were considered statistically significant.Results:Thirty-one of 122 players had elbow pain. The hip flexion angle of the trail leg was 121.9° ± 12.3° for the normal group and 111.2° ± 11.3° for the pain group (P = .0001). The plant leg hip flexion angles were 122.0° ± 12.4° and 113.6° ± 11.3° (P = .0014) for the normal and pain groups, respectively. The internal rotation angle at 0° of hip flexion of the trail leg was 49.4° ± 12.6° and 45.6° ± 8.8° (not significant), and of the plant leg was 49.1° ± 12.5° and 48.7° ± 11.5° (not significant), for the normal and pain groups, respectively. The internal rotation of the trail leg at 90° of hip flexion was 46.9° ± 13.3° in the normal group and 36.1° ± 15.7° in the pain group (P = .0005). In the plant leg, the internal rotation angle at 90° of hip flexion was 46.9° ± 12.2° and 36.4° ± 18.1° for the normal and pain groups, respectively (P = .0013).Conclusion:Limitations to hip flexion and internal rotation at 90° of hip flexion were risk factors for elbow injury. Differences in internal rotation angles between 0° and 90° of hip flexion may be important criteria for identifying adolescent baseball players at risk of elbow pain.
The relationship between bilateral transfer and the effect of motor learning schedule was investigated using a palm force-retaining task. Thirty-three study subjects, all of whom were right-handed, were randomly divided into 2 groups, and each group was subjected to a separate practice schedule. The task was to generate and retain a force of 400 g using the right index finger for pressure. One session of practice consisted of 5 trials, and a total of 5 sessions (25 trials) were carried out exclusively with the right hand. Of the two groups, one group was set as a massed practice group (MP Group), and the other was a distributed practice group (DP Group). The former underwent an intensive practice schedule by carrying out 5 sessions of practice a day with a 1-minute recess every session, and the latter underwent a 5-day consecutive practice schedule by carrying out 1 session of practice a day. In the practice phase, visual feedback (VF) was given following the end of each trial. All of the study subjects underwent the initial test prior to the practice and retention tests at 5 minutes, 1 day and 4 days after the end of the final session of practice, without receiving VF. The data analysis was carried out by calculating the root mean squared error (RMSE). In the practice phase of the right hand, a decrease in RMSE was observed in both groups. In the retention tests of the right hand, there was a difference between these groups. The DP Group showed higher learning-retention ability, demonstrating the effect of the practice schedule. Regarding the left hand, the RMSE values in the retention tests were lower than the value observed in the initial test. This demonstrates that practice of the right hand gives a positive effect on the left hand. In addition, although no significant difference in the retention tests of the left hand was observed between these groups, the DP Group showed a tendency of higher learning-retention ability. This suggests that the practice schedule affects the effect on the non-practiced side as well.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.